This invention relates to serial communications, and more particularly, to serial communications protocols having a data path with optional features.
Serial communications formats are often used in modern electronics systems. Serial communications can be faster than parallel communications, use fewer pins, and, particularly when differential signaling schemes are used, can have higher noise immunity.
It can be challenging to handle serial data streams at high data rates (e.g., at data rates above several Gbps). As a result, it is often advantageous to support high-speed serial data communications using multiple smaller serial data paths (lanes) operating in parallel.
A number of functions are involved in controlling the operation of a successful serial communications link. Serial communications protocols in which these functions are mandatory can become “heavy” and require a large amount of resources to implement on an integrated circuit. Serial communications protocols that do not support these functions do not require as many resources to implement, but can be inadequate for many communications tasks.